Welding device and welding method for hemispherical harmonic oscillator and excitation cover

Abstract

The invention relates to a welding device, in particular to a hemispherical harmonic oscillator and excitation cover welding device and method. The problems that when an existing harmonic oscillator and an excitation cover are welded in an indium sealing mode, heating time is long, indium is prone to oxidation, welding reliability is poor, the flowing depth of indium cannot be checked in real time, consequently, the harmonic oscillator is fixed unreliably, and the assembly precision of the excitation cover and the harmonic oscillator cannot be guaranteed are solved. The excitation cover and the hemispherical harmonic oscillator are fixed through the welding base tool, the laser generator can reciprocate in the vertical direction through the sliding mechanism during welding, the welding base tool is driven to rotate through the rotating disc, and indium is evenly heated during welding; internal air is pumped out through the degassing port, a low-vacuum environment is created in the excitation cover, the influence of indium oxidation on the flowability is prevented, and non-contact indium seal welding is realized; and the laser heating efficiency is high, the welding reliability is high, a drying oven is not needed for heating, and the assembly precision of the excitation cover and the harmonic oscillator is guaranteed.

Description

Technical Field

[0001] The invention relates to a welding device, in particular to a welding device and a welding method for a hemispherical resonator and an excitation cover. Background Art

[0002] Hemispherical resonator gyroscope has gradually become a research hotspot in the field of inertial instruments due to its high precision, high reliability, long life, small size and radiation resistance. The fused quartz resonator is the core part of the hemispherical resonator gyroscope. The resonator is welded to the excitation cover through a micro gap, and indium sealing welding is currently a more commonly used resonator welding technology and is widely used in the field of welding resonators and excitation covers.

[0003] The quality factor (Q value) of the resonator is one of the key indicators to measure the vibration characteristics of the resonator. The higher the Q value, the longer the resonator can maintain vibration, which can greatly reduce the interference introduced by the applied vibration energy, which is beneficial to improving the accuracy of the gyroscope. However, after the assembly and welding of the resonator, the excitation cover and the detection base are completed, the Q value of the resonator will be greatly lost due to the influence of welding materials and assembly stress, resulting in a decrease in the performance of the hemispherical resonator gyroscope.

[0004] There are currently two main methods for welding resonators:

[0005] First, during the resonator welding process, an electric soldering iron is used to locally heat the end of the excitation cover, and the indium inside the gap is melted by heat conduction, thereby realizing the resonator welding. However, since the resonator and the excitation cover are both made of molten quartz glass, their thermal conductivity is poor. When indium sealing welding is used, the indium inside the matching gap cannot be effectively welded by heating the end. The heating time is too long, and indium is easily oxidized in the air. The oxidized indium is mixed in the gap, which reduces the fluidity of indium inside the gap. Indium is unevenly filled inside the gap, the effective welding area is reduced, and the insufficient amount of indium filling leads to poor welding reliability. In addition, the resonator is not firmly fixed at the welding site, which leads to the accelerated dissipation of the resonator vibration energy. Therefore, the Q value of the resonator is greatly lost after assembly.

[0006] The second is to pre-assemble the resonator and the excitation cover and then put them into an oven for overall heating. This method can realize the indium sealing welding of the resonator, but due to the poor thermal conductivity of the glass material, the welding time is long, and the flow depth of indium cannot be checked in real time in the oven, which easily leads to insufficient welding depth or excessive welding. Insufficient welding depth will cause unreliable fixation of the resonator, while excessive welding will cause indium to fall from the gap and damage the hemispherical resonator, resulting in welding failure. In addition, the oven will vibrate during the heating process, and the assembly accuracy of the resonator and the excitation cover cannot be guaranteed. Summary of the invention

[0007] The purpose of the present invention is to solve the technical problems that the indium seal welding between the existing resonator and the excitation cover has long heating time, indium is easy to oxidize, welding reliability is poor, the indium flow depth cannot be checked in real time, resulting in unreliable fixation of the resonator, and the assembly accuracy of the excitation cover and the resonator cannot be guaranteed, and to provide a hemispherical resonator and excitation cover welding device and welding method.

[0008] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0009] A device for welding a hemispherical resonator and an excitation cover is used for welding a hemispherical resonator and an excitation cover, wherein the hemispherical resonator comprises an umbrella handle and a hemispherical shell arranged on the umbrella handle, the excitation cover comprises a hemispherical groove for accommodating the hemispherical shell and opening downward, and a through hole vertically arranged at the top center of the hemispherical groove for matching with the umbrella handle, and a gap exists between the umbrella handle and the through hole after the umbrella handle is placed in the through hole, and the gap is a welding gap, and the device is special in that it comprises a fixing frame, a laser generator, an electric heating block, a welding base tooling and a rotating disk;

[0010] The laser generator is connected to the fixed frame through a sliding mechanism, and the laser generator can move in a vertical direction through the sliding mechanism;

[0011] The rotating disc is arranged relative to the laser generator and mounted on the fixed frame, the welding base tooling is coaxially mounted on the rotating disc, and the rotating disc can drive the welding base tooling to rotate;

[0012] The upper end of the welding base tooling is coaxially provided with a step-shaped groove, including a first groove and a second groove, the first groove is located at the top of the second groove and the diameter of the first groove is larger than the second groove, so that the bottom of the first groove forms a step surface of the step-shaped groove; the step surface of the step-shaped groove is used to cooperate with the lower end surface of the excitation cover, and the inner wall of the first groove is used to cooperate with the side wall of the excitation cover; the electric heating block is installed on the top end surface of the excitation cover and is arranged corresponding to the through hole position of the excitation cover;

[0013] A degassing port is radially opened on the side wall of the welding base tooling corresponding to the position of the second groove, which is used to connect with an external degassing device. An annular mounting groove is set at the bottom center of the second groove, and the annular mounting groove is used to fix the bottom end of the umbrella handle of the hemispherical resonator, so that a welding gap is formed between the top end of the umbrella handle and the through hole.

[0014] Furthermore, the fixed frame includes a horizontal frame and a vertical frame vertically arranged on one side of the horizontal frame, the laser generator is connected to the vertical frame through a sliding mechanism, and the rotating disk is installed on the horizontal frame.

[0015] Furthermore, the sliding mechanism comprises a lifting track arranged on the vertical frame along the vertical direction, and the laser generator is slidably assembled on the lifting track.

[0016] Furthermore, a degassing conduit is provided in the degassing port, and the degassing conduit is used to be connected to an external degassing device.

[0017] Furthermore, the fixing frame and the welding base tooling are made of stainless steel; and the degassing duct is made of copper alloy.

[0018] At the same time, the present invention also provides a method for welding a hemispherical resonator and an excitation cover, using the above-mentioned hemispherical resonator and an excitation cover welding device, characterized in that it includes the following steps:

[0019] S1 Clean the welding base tooling to ensure that the surface is clean and free of dust or particles;

[0020] S2: assemble the excitation cover and the hemispherical resonator and place them into the welding base tooling, wherein the lower end surface of the excitation cover abuts against the step surface of the step-shaped groove, and the side wall abuts against the inner wall of the first groove; the handle of the hemispherical resonator is located in the through hole of the excitation cover, and the bottom end of the handle is located in the annular mounting groove; the hemispherical shell of the hemispherical resonator is located in the hemispherical groove of the excitation cover, and a matching gap is left between the two;

[0021] S3: Fill the indium sheet with a thickness of less than 0.05 mm into the welding gap to form an indium filling area, observe the filling depth, and stop when the indium sheet is 3 mm away from the hemispherical shell, and ensure that the circumferential filling is sufficient;

[0022] S4 starts the laser generator and adjusts the focal length so that the laser spot falls on the indium filling part, and starts the external degassing device;

[0023] S5: pre-filling a portion of indium solder on the top surface of the excitation cover, installing the electric heating block on the top surface of the excitation cover and setting it corresponding to the through hole position, and then starting the electric heating block;

[0024] S6 adjusts the height position of the laser generator through the sliding mechanism so that the laser spot is located at the lower end of the indium filling part;

[0025] S7 starts the rotating disk. When the rotating disk drives the indium filling part to rotate, the laser spot generated by the laser generator moves back and forth up and down on the indium filling part through the sliding mechanism, so that the indium is evenly heated;

[0026] S8 After each soldering for 1 minute, the indium solder pre-filled on the top surface of the excitation cover is removed and replaced with new indium solder;

[0027] S9: Continue to observe. If the indium is observed to flow to 2 mm from the hemispherical shell, then execute step S10. If not, then return to step S7.

[0028] S10 turns off the laser generator, the external degassing device, the rotating disk and the electric heating block, and waits for the electric heating block, the excitation cover and the welding base tooling to cool naturally to room temperature, completing the welding of the hemispherical resonator and the excitation cover.

[0029] Furthermore, in the step S1, an organic solvent is used to clean the welding base tooling.

[0030] Furthermore, in step S5, the electric heating block is started by supplying direct current, and the current is 3A.

[0031] Further, in step S4, the power of the laser generator is 2-5W.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention provides a hemispherical resonator and excitation cover welding device, which installs and fixes the excitation cover and the hemispherical resonator through a welding base tooling, and the laser generator can be moved in the vertical direction through a sliding mechanism during welding, and the welding base tooling is driven to rotate by a rotating disk, so that indium can be evenly heated during welding, and the internal air is extracted through the degassing port to create a low vacuum environment inside the excitation cover to prevent indium oxidation from affecting fluidity during welding, thereby realizing contactless indium sealing welding, with high laser heating efficiency and high welding reliability, and no need to use an oven for heating, thereby ensuring the assembly accuracy of the excitation cover and the resonator.

[0034] (2) In a method for welding a hemispherical resonator and an excitation cover of the present invention, indium solder is pre-filled on the top surface of the excitation cover. By continuous heating by an electric heating block, indium can be continuously added to the welding gap. In addition, the pre-filled indium solder can prevent the indium in the welding gap from coming into contact with air and being oxidized.

[0035] (3) In the welding method of a hemispherical resonator and an excitation cover of the present invention, when filling the indium sheet, the indium sheet is stopped when it is 3 mm away from the hemispherical shell. This can prevent the initial stage of indium melting from falling directly from the bottom of the welding gap to the hemispherical shell, affecting the accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of an embodiment of a hemispherical resonator and an excitation cover welding device of the present invention in a use state;

[0037] Figure 2 It is a schematic diagram of the coordination of the hemispherical resonator, the excitation cover, the welding tooling base and the electric heating block in an embodiment of the present invention.

[0038] The following are the descriptions of the reference numerals:

[0039] 1-fixed frame, 11-horizontal frame, 12-vertical frame; 2-laser generator, 3-electric heating block, 4-welding base tooling, 41-first groove, 42-second groove, 43-annular mounting groove; 5-rotating disc, 6-degassing duct, 7-excitation cover, 71-hemispherical groove; 8-hemispherical resonator, 81-umbrella handle, 82-hemispherical shell; 9-lifting track. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and exemplary embodiments.

[0041] The structure of the hemispherical resonator 8 and the excitation cover 7 used for welding of the present invention is as follows: Figure 2 As shown, both are made of fused quartz glass, the hemispherical resonator 8 includes an umbrella handle 81 and a hemispherical shell 82 arranged on the umbrella handle 81, and the excitation cover 7 includes a hemispherical groove 71 for accommodating the hemispherical shell 82 and with an opening facing downward, and a through hole vertically arranged at the top center of the hemispherical groove 71 for matching with the umbrella handle 81. When the umbrella handle 81 is placed in the through hole, there is a gap between the through hole and the umbrella handle, and the gap is a welding gap.

[0042] Reference Figure 1-Figure 2 A hemispherical resonator and excitation cover welding device of the present invention includes a fixing frame 1, which is L-shaped and made of stainless steel to ensure structural strength. The fixing frame 1 includes a horizontal frame 11 and a vertical frame 12 vertically arranged on one side of the horizontal frame 11. A sliding mechanism is arranged on the vertical frame 12, and a laser generator 2 is connected to the vertical frame 12 through the sliding mechanism. In this embodiment, the sliding mechanism includes a lifting track 9 arranged on the vertical frame 12 in the vertical direction, and the laser generator 2 is slidably assembled on the lifting track 9. The laser generator 2 can move in the vertical direction through the lifting track 9.

[0043] A rotating disc 5 is provided at a position relative to the laser generator 2, which is mounted on the horizontal frame 11. A welding base tool 4 is coaxially mounted on the rotating disc 5. The rotating disc 5 can drive the welding base tool 4 to rotate. The structure of the welding base tool 4 is as shown in FIG. Figure 2 As shown, a stepped groove is coaxially arranged at its upper end, including a first groove 41 and a second groove 42. The diameter of the first groove 41 is larger than the diameter of the second groove 42 and the first groove 41 is located at the top of the second groove 42, so that the bottom of the first groove 41 forms a stepped surface of the stepped groove, and the stepped surface of the stepped groove is used to abut with the lower end surface of the excitation cover 7, and the inner wall of the first groove 41 is used to abut with the side wall of the excitation cover 7. An annular mounting groove 43 is arranged at the bottom of the second groove 42. When the bottom end of the umbrella handle 81 is inserted into the annular mounting groove 43, the annular mounting groove 43 can fix the position of the umbrella handle 81, so that a welding gap is formed between the umbrella handle 81 and the through hole.

[0044] When the excitation cover 7 is placed in the welding base fixture 4, the electric heating block 3 is installed on the top surface of the excitation cover 7 and is arranged corresponding to the through hole position of the excitation cover 7. The welding base fixture 4 is made of stainless steel material to ensure structural strength.

[0045] In order to prevent indium oxidation during welding, a degassing port is radially opened on the side wall of the welding base tooling 4 at a position corresponding to the second groove 42, and a degassing duct 6 is arranged in the degassing port. The degassing duct 6 is made of copper alloy and is connected to an external degassing device. Air can be extracted during welding to form a low vacuum environment in the excitation cover 7.

[0046] At the same time, the present invention also provides a method for welding a hemispherical resonator and an excitation cover, which adopts the above-mentioned device for welding a hemispherical resonator and an excitation cover, and comprises the following steps:

[0047] S1 uses organic solvent to clean the welding base tooling 4 to ensure that the surface is clean and free of dust or particles;

[0048] S2: assemble the excitation cover 7 and the hemispherical resonator 8 and place them in the welding base tooling 4, the lower end surface of the excitation cover 7 abuts against the step surface of the step-shaped groove, and the side wall abuts against the inner wall of the first groove 41; the top end of the umbrella handle 81 of the hemispherical resonator 8 is located in the through hole of the excitation cover 7, the bottom end of the umbrella handle 81 is located in the annular mounting groove 43, and the hemispherical shell 82 of the hemispherical resonator 8 is located in the hemispherical groove 71 of the excitation cover 7, and a matching gap is left between the two;

[0049] S3: Fill the indium sheet with a thickness of less than 0.05 mm into the welding gap to form an indium filling area, observe the filling depth, and stop when the indium sheet is 3 mm away from the hemispherical shell 82, and ensure that the circumferential filling is sufficient;

[0050] S4 starts the laser generator 2 with a power of 2-5W, adjusts the focal length so that the laser spot falls on the indium filling part, and starts the external degassing device;

[0051] S5: pre-filling a portion of indium solder on the top surface of the excitation cover 7, installing the electric heating block 3 on the top surface of the excitation cover 7 and setting it corresponding to the through hole position, and then supplying direct current to start the electric heating block 3, with a current of 3A;

[0052] S6 adjusts the height position of the laser generator 2 through the sliding mechanism so that the laser spot is located at the lower end of the indium-filled part;

[0053] S7 starts the rotating disk 5. When the rotating disk 5 drives the indium filling part to rotate, the laser spot generated by the laser generator 2 moves back and forth up and down on the indium filling part through the sliding mechanism, so that the indium is evenly heated;

[0054] S8 After each soldering for 1 minute, the indium solder pre-filled on the top surface of the excitation cover 7 is removed and replaced with new indium solder;

[0055] S9: Continue to observe. If the indium is observed to flow to 2 mm from the hemispherical shell 82, then execute step S10. If not, then return to step S7.

[0056] S10 turns off the laser generator 2, the external degassing device, the rotating disk 5 and the electric heating block 3, and waits for the electric heating block 3, the excitation cover 7 and the welding base tooling 4 to naturally cool to room temperature, completing the welding of the hemispherical resonator 8 and the excitation cover 7.

[0057] In step S5, indium solder is pre-filled on the top surface of the excitation cover 7 to prevent the indium in the welding gap from being oxidized by contact with air. In step S8, new indium solder is replaced after every 1 minute of welding to prevent the indium oxidized on the top surface of the excitation cover 7 from flowing into the welding gap. In step S4, the power of the laser generator 2 is 2-5W. If the power is too large, the indium will melt too quickly and damage the excitation cover 7 and the hemispherical resonator 8.

[0058] The embodiments described above are merely descriptions of specific implementation methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A hemispherical resonator and an excitation cover welding device, used for welding a hemispherical resonator (8) and an excitation cover (7), wherein the hemispherical resonator (8) comprises an umbrella handle (81) and a hemispherical shell (82) arranged on the umbrella handle (81), and the excitation cover (7) comprises a hemispherical groove (71) for accommodating the hemispherical shell (82) and opening downward, and a through hole vertically arranged at the top center of the hemispherical groove (71) for matching with the umbrella handle (81), and a gap exists between the umbrella handle (81) and the through hole after the umbrella handle (81) is placed in the through hole, and the gap is a welding gap, characterized in that: It comprises a fixed frame (1), a laser generator (2), an electric heating block (3), a welding base tool (4) and a rotating disc (5); The laser generator (2) is connected to the fixed frame (1) via a sliding mechanism, and the laser generator (2) can move in a vertical direction via the sliding mechanism; The rotating disk (5) is arranged relative to the laser generator (2) and is mounted on the fixed frame (1); the welding base tooling (4) is coaxially mounted on the rotating disk (5); and the rotating disk (5) can drive the welding base tooling (4) to rotate; The upper end of the welding base tool (4) is coaxially provided with a step-shaped groove, including a first groove (41) and a second groove (42), the first groove (41) is located at the top of the second groove (42) and the diameter of the first groove (41) is larger than that of the second groove (42), so that the bottom of the first groove (41) forms a step surface of the step-shaped groove; the step surface of the step-shaped groove is used to cooperate with the lower end surface of the excitation cover (7), and the inner wall of the first groove (41) is used to cooperate with the side wall of the excitation cover (7); the electric heating block (3) is installed on the top end surface of the excitation cover (7) and is arranged corresponding to the through hole position of the excitation cover (7); A degassing port is radially provided on the side wall of the welding base tooling (4) corresponding to the position of the second groove (42) for connecting to an external degassing device, and an annular mounting groove (43) is provided at the bottom of the second groove (42). The annular mounting groove (43) is used to fix the bottom end of the umbrella handle (81) of the hemispherical resonator (8) so that a welding gap is formed between the top end of the umbrella handle (81) and the through hole.

2. The device for welding a hemispherical resonator and an excitation cover according to claim 1, characterized in that: The fixed frame (1) comprises a horizontal frame (11) and a vertical frame (12) vertically arranged on one side of the horizontal frame (11); the laser generator (2) is connected to the vertical frame (12) via a sliding mechanism; and the rotating disc (5) is mounted on the horizontal frame (11).

3. The device for welding a hemispherical resonator and an excitation cover according to claim 2, characterized in that: The sliding mechanism comprises a lifting track (9) arranged on a vertical frame (12) in a vertical direction, and the laser generator (2) is slidably assembled on the lifting track (9).

4. The device for welding a hemispherical resonator and an excitation cover according to any one of claims 1 to 3, characterized in that: A degassing conduit (6) is arranged in the degassing port, and the degassing conduit (6) is used to be connected to an external degassing device.

5. The device for welding a hemispherical resonator and an excitation cover according to claim 4, characterized in that: The fixing frame (1) and the welding base tooling (4) are made of stainless steel; and the degassing duct (6) is made of copper alloy.

6. A method for welding a hemispherical resonator and an excitation cover, using the device for welding a hemispherical resonator and an excitation cover as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: S1 Clean the welding base tooling (4) to ensure that the surface is clean and free of dust or particles; S2: assemble the excitation cover (7) and the hemispherical resonator (8) and place them in the welding base tool (4); the lower end surface of the excitation cover (7) abuts against the step surface of the step-shaped groove, and the side wall abuts against the inner wall of the first groove (41); the top end of the umbrella handle (81) of the hemispherical resonator (8) is located in the through hole of the excitation cover (7), the bottom end of the umbrella handle (81) is located in the annular mounting groove (43), and the hemispherical shell (82) of the hemispherical resonator (8) is located in the hemispherical groove (71) of the excitation cover (7), and a matching gap is left between the two; S3: Filling an indium sheet with a thickness of less than 0.05 mm into the welding gap to form an indium filling area, observing the filling depth, and stopping when the indium sheet is 3 mm away from the hemispherical shell (82), and ensuring that the circumferential filling is sufficient; S4: start the laser generator (2) and adjust the focal length so that the laser spot falls on the indium filling part, and start the external degassing device; S5: pre-filling a portion of indium solder on the top surface of the excitation cover (7), installing the electric heating block (3) on the top surface of the excitation cover (7) and arranging it corresponding to the position of the through hole, and then starting the electric heating block (3); S6 adjusts the height position of the laser generator (2) through a sliding mechanism so that the laser spot is located at the lower end of the indium-filled portion; S7 starts the rotating disk (5), and when the rotating disk (5) drives the indium filling part to rotate, the laser spot generated by the laser generator (2) moves back and forth up and down on the indium filling part through the sliding mechanism, so that the indium is evenly heated; S8 After each minute of soldering, the indium solder pre-filled on the top surface of the excitation cover (7) is removed and replaced with new indium solder; S9: continue to observe, if the indium is observed to flow to 2 mm from the hemispherical shell (82), then execute step S10, if not observed, then return to step S7; S10 turns off the laser generator (2), the external degassing device, the rotating disk (5) and the electric heating block (3), waits for the electric heating block (3), the excitation cover (7) and the welding base tooling (4) to naturally cool to room temperature, and completes the welding of the hemispherical resonator (8) and the excitation cover (7).

7. The method for welding a hemispherical resonator and an excitation cover according to claim 6, characterized in that: In the step S1, an organic solvent is used to clean the welding base tooling (4).

8. The method for welding a hemispherical resonator and an excitation cover according to claim 7, characterized in that: In the step S5, the electric heating block (3) is started by supplying direct current, and the current is 3A.

9. The method for welding a hemispherical resonator and an excitation cover according to claim 8, characterized in that: In step S4, the power of the laser generator (2) is 2-5W.

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